1. Field of the Invention
The present invention relates to a transparent type liquid crystal display device.
2. Background Art
For example, a transparent type liquid crystal display panel of an IPS system is configured such that liquid crystal is retained between an array substrate at which a thin film transistor and the like are formed and a filter substrate (counter substrate) which faces the array substrate and at which color filters and the like are formed. A region of the array substrate corresponding to the display region of the liquid crystal display panel (hereinafter referred to as the display region of the array substrate) exists inside an encapsulated region where the liquid crystal is retained. A terminal portion of the array substrate for connecting a driving board and a driver IC exists outside the encapsulated region without facing the filter substrate. Contact holes are formed in the display region and the terminal portion (hereinafter, the hole in the display region and the hole in the terminal portion are respectively described as a pixel contact hole and a terminal portion contact hole).
FIG. 15 is a cross sectional view of a conventional pixel contact hole and terminal portion contact hole. The cross sectional view of the pixel contact hole is shown on the left side of the drawing, and the cross sectional view of the terminal portion contact hole is shown on the right side of the drawing. A wiring electrode PLE below the pixel contact hole is composed of three layers of a cap layer PMC, a wiring metal layer PM, and a barrier layer PMB in this order from the top. A wiring electrode TLE below the terminal portion contact hole is composed of three layers of a cap layer TMC, a wiring metal layer TM, and a barrier layer TMB in this order from the top. A lower inorganic protective layer PSL is disposed on the wiring electrodes PLE and TLE. An organic protective layer PSF is formed on the lower inorganic protective layer PSL excepting the pixel contact hole and the terminal portion contact hole as viewed in a plane. An upper inorganic protective layer PSU is disposed on the organic protective layer PSF including the inner periphery portions of the pixel contact hole and the terminal portion contact hole. The pixel contact hole penetrates through the upper inorganic protective layer PSU and the lower inorganic protective layer PSL. A pixel electrode PX formed by patterning a layer of a transparent electrode is in contact with the cap layer PMC of an electrode film at the bottom of the pixel contact hole. The terminal portion contact hole also penetrates through the upper inorganic protective layer PSU and the lower inorganic protective layer PSL. A terminal protection electrode TE formed by patterning the same layer of the transparent electrode is in contact with the cap layer TMC of the electrode film at the bottom of the terminal portion contact hole. Although not shown, an inter-layer insulating film, a gate electrode film, and the like are present below the electrode film in the drawing. A common electrode CT is present between the organic protective layer PSF and the upper inorganic protective layer PSU in a region of a part of the vicinity of the pixel contact hole.
JP-A-2008-15345 is a document relating to the present application, in which a contact hole formed in a pixel circuit of a semi-transparent type liquid crystal display device is disclosed.